Pedestal housings used in “outside plant” infrastructure for communications and utility companies often house active electronic components which generate heat. The temperature inside the housing increases above ambient conditions due to the heat generated from the active components as well as direct and indirect solar exposure and radiant heat from other objects around the housing. The increase in the internal temperature of the housing transfers heat to the electronic components with adverse consequences. These components tend to fail at shorter and shorter intervals with increases in temperature or operate at reduced rates. As communications companies increase data rates to customers, more active electronics are placed in the outside infrastructure and the higher data rates typically require active components that generate more heat and are more prone to temperature induced failures. There have been many attempts to mitigate the heat build up with venting and fans to help remove heated air from inside the housing with various degrees of success. However the drive to more powerful electronics has created a need for better solutions to the total heating problem.
Prior solutions utilized an additional plastic part over the top of the pedestal known as an attic to improve the looks and strength of larger pedestals. It had the additional effect of adding a layer of plastic and airspace, with venting, to the top of the pedestal. In the early days of cable taps and amplifiers this helped with heat load but as power levels increased and electronic components became more sensitive to temperature increases, a layer of fiberglass insulation was added to reduce heat transfer from the attic to the inside of the housing. Over the last several years the industry reached a point where those measures were no longer effective by themselves. The next phase involved much greater venting in the sides of the pedestal as well as large vent holes in the top of the pedestal but underneath the attic for weather protection. Additionally, the holes under the attic were designed to allow for direct attachment of cooling fans in extreme conditions. However, the use of fans introduced its own set of problems as they had to be powered, which increased the power transmission requirements to the pedestal and they introduced electronic noise into the system. They were also prone to failure, which necessitated replacement and additional maintenance costs. These changes reduced the heat build up inside the housing but were still inadequate and the use of fans was not an acceptable long term solution.